Shot propelling arrow

ABSTRACT

A tubular arrow shaft is sealed at its nocked end portion. The seal and a slidable piston in the shaft retain a compressible fluid therebetween. Forwardly of the piston, a plurality of projectiles are aligned axially in the shaft. The forward acceleration of the arrow by a bow and the inertia of the projectiles compresses the retained fluid while accelerating the projectiles up to the arrow velocity. Thereafter, the fluid expansion causes substantially all the energy of the arrow to be transferred to the projectiles which are propelled toward a target while the arrow falls to the ground within a few feet of the bow.

[22] Filed:

nited States Patent 191 Curran et al.

1 1 SHOT PROPELLING ARROW [75] Inventors: Roger J. Curran, Stratford;Kenneth W. Misevich, Fairfield, both of Conn.

[73] Assignee: Remington Arms Company, Inc.,

Bridgeport, Conn.

Nov. 8, 1972 [21] Appl. No.: 304,665

[52] U.S. Cl 273/1065 R [51] Int. Cl F411) 5/02 [58] Field Of Search273/1065 R [56] References Cited UNITED STATES PATENTS 3,021,139 2/1962Buerosse 273/1065 R 3,077,876 2/1963 Richter 273/1065 R X 3,586,3326/1971 Alban 273/1065 R [11] 3,822,884 July 9,1974

Primary ExaminerRichard C. Pinkham Assistant Examiner-Paul E. ShapiroAttorney, Agent, or Firm-John H. Lewis, Jr.; Nicholas Skovran; Joel D.Talcott [57] ABSTRACT A tubular arrow shaft is sealed at its nocked endportion. The seal and a slidable piston in the shaft retain acompressible fluid therebetween. Forwardly of the piston, a plurality ofprojectiles are aligned axially in the shaft. The forward accelerationof the arrow by a bow and the inertia of the projectiles compresses theretained fluid while accelerating the projectiles up to the arrqwvelocity. Thereafter, the fluid expansion causes substantially all theenergy of the arrow to be transferred to the projectiles which arepropelled I toward a target while the arrow falls to the ground within afew feet of the bow. 15 Claims, 5 Drawing Figures 1 snor PROPELLINGARROW This invention relates to arrows and more particularly to an arrowfor propelling a plurality of projectiles to a target.

With a recent expanded interest in archery, increasing numbers ofsportsmen have been turning to the bow and arrow for shooting bothtargets and game. This interest has been due in part to archerys lowcost as well as a desire for more simple and primitive hunting means.

However, standard arrows are only effective when used for shooting atfixed targets or hunting animals of moderate size because only a singleprojectile, the arrow itself, is capable of striking the target. Smallgame and birds, as well as the clay targets used in skeet and trapshooting, cannot effectively be used as targets of conventional arrows.

For this reason, there have been attempts to provide arrows capable ofpropelling a plurality of projectiles with a single arrow shot. Typicalof these is US. Pat. No. 2,970,838 issued to Wilmer R. Taggert on Feb.7, 1961. This patent discloses an arrow having a massive head holding aplurality of projectiles. After the arrow is fired, the projectiles arereleased, and the arrow is slowed aerodynamically to effect separation.

US. Pat. No. 3,021,139, issued to Henry P. Buerosse on Feb. 13, 1962,discloses an arrow head capable of projecting shot particles ahead of anarrow during flight. A spring is compressed during acceleration of thearrow on the bow and expands during flight separating the shot chargefrom the arrow by applying equal forces to each. The arrow is againdecelerated primarily by aerodynamic drag.

Prior art shot arrows are incapable of transferring a significant amountof energy to the projectiles. Rather, much of the energy from the bow isretained by the massive arrow which therefore travels a significantdistance down range making recovery difficult. More significantly,because of the limited transfer of energy from the arrow to theprojectiles, largely due to the high mass and resultant low velocitiesof prior art arrows, and the large number of projectiles among whichthis energy is divided, the released projectiles may not have sufficientenergyto kill small game or even break a clay target.

The shot propelling arrow of this invention overcomes these and otherrelated limitations. The shot arrow of this invention generallycomprises a tubular shaft sealed at its nocked end, the seal and aslidable piston retaining a'compressible fluid therebetween. A pluralityof shot particles are aligned along the longitudinal axis of the shaftand forwardly of the piston. Holding means may be used at an openforward end portion to retainshot particles in the shaft duringpositioning of the arrow on the bow, but not significantly slowing theirvelocity upon release.

When the arrow is released from a drawn bow, the shaft acceleratesquickly while the shot only accelerates as the fluid pressure increases.The fluid is compressed by the inertial forces of the projectiles, untilat an extreme high pressure the velocity of the shot reaches that of thearrow. The compressed fluid then acts equally on the arrow and the shotfurther accelerating the shot particles while decelerating the arrow.All of the energy of the arrow is subsequently transferred to the shot.Sufficient energy is thus imparted to the shot particles to effectivelykill small game while the arrow falls to the ground within a few feet ofthe bow.

It is an object of this invention to provide an arrow capable ofeffectively propelling a plurality of projectiles toward a target.

It is another object of this invention to provide an arrow capable ofpropelling a plurality of projectiles with sufficient energy for huntingsmall game or shooting skeet or trap targets.

It is still another object of this invention to provide a shotpropelling arrow which falls to the ground in close proximity of the bowfor easy retrieval after its projectiles have been released.

These and other objects and advantages of this invention will becomeapparent from the following specification when read in connection withthe drawings wherein:

FIG. 1 illustrates an archer firing a shot propelling arrow of thisinvention from a bow;

"FIG. 2 is a fragmentary sectional view of a shot propelling arrow ofthis invention;

FIG. 3 is a fragmentary sectional view of the shot propelling arrow ofFIG. 2 wherein alternate embodiments of certain components of the arroware shown;

FIG. 4 is a fragmentary sectional view of the shot propelling arrow ofthis invention showing additional embodiments of arrow components; and

FIG. 5 is a fragmentary sectional view illustrating adjusting means forthe shot propelling arrow of this invention.

Referring now to FIG. I, a shot arrow 11 is shown nocked on a bowstring12 of a standard bow 14. It can be seen that the shot arrow 11 of thisinvention is fired from the bow 14 in substantially the same manner as astandard arrow.

The shot arrow 11 is best described with reference to FIG. 2 and hasatubular shaft 15 which has an open forward end portion 15a and a rearend portion 15b to which a nock 16 is attached by any suitable means. Aseal 17, preferably molded of a suitable plastic, is mounted at the rearend portion 15b of the shaft 15 to prevent the passage of airtherethrough and may have a forwardly extending obturating rim 17a. Acompression chamber 18 is defined in the shaft 15 between the seal 17and a piston 19 which is preferably molded of a suitable plastic such ashigh density polyethylene and is slidably mounted in the shaft 15. Thepiston 19 preferably has av rearwardly extending obturating rim 19awhich enhances the air-sealing ability of the piston 19; the piston mayalso have a concave forward end portion 19b shaped to accommodate a shotparticle 20 and a threaded opening to facilitate adjustment of thepiston 19 in a manner which will subsequently be further described. Aplurality of metallic shot particles 20 are fitted into the shaft 15forwardly of the piston 19. The shot particles 20 are preferablyspherical steel projectiles having a diameter only slightly less thanthe inner diameter of the shaft 15 so that they form a single line ofprojectiles within the shaft. This arrangement prevents any jammingwhich might occur were significantly smaller particles used. The shotarrow 1 l is preferably constructed to propel roughly 15 to 30projectiles, the number depending upon the energy required perprojectile. A modern bow can transfer about 20 ft. lb. to an arrow soif, for example, 1 ft. lb. per projectile were required, about 20 shotparticles would be used.

Although fletching may be added to the shot arrow 11, it is notnecessary or desired for proper operation of the shot arrow.

In the preferred embodiment, the shaft preferably has an inner diameterof about 0.265 in. while the shot particles have a diameter of 0.250 in.If shot particles are used, each preferably having a weight of about 1gram, the weight of the shot propelling arrow is preferably about thesame weight of the projectiles or about 20 grams.

Operation of the shot arrow of this invention will now be described. Theshot arrow 11, loaded with a plurality of shot particles 20, is firedfrom a conventional bow 14 (FIG. 1) in a manner substantially the sameas for the firing of a conventional arrow. The shot arrow 11 is nockedon the bowstring 12, and the bowstring is drawn back from its restposition to the full draw position illustrated in FIG. 1. When thebowstring 12 is released, the limbs of the bow 14, through the bowstringl2, exert a force accelerating the shot arrow 11 in a manner well knownto those skilled in the art.

Referring now to FIG. 2, while the shaft 15 is being accelerated by thebowstring, the shot particles 20 and, accordingly, the piston 19 remainsubstantially fixed in position relative to the bow 14 due to inertia sothat the seal 17 is effectively accelerated toward the piston 19. Thisaction compresses the air which is trapped in the compression chamber 18by the sealing action of the obturating rims 17a and 190. As th speed ofthe shaft 15 increases, the pressure of this trapped air increases andapplies a forwardly directed force to the piston 19 as shown by thearrow 24 in FIG. 2. This force causes forward acceleration of the piston19 and shot 20, which acceleration is, however, at a much slower ratethan that of the shaft.

As the seal 17 approaches the piston 19, the volume of the trapped airdecreases further, thereby increasing its pressure. When the seal 17very closely approaches the piston 19, the pressure increases at a muchgreater rate reaching anextremely high value, on the order of 10,000psi, when the seal and piston come roughly within one-quarter inch ofeach other. This high pressure produces a corresponding high force onthe piston 19, sufficient to overcome the inertia of the shot particles,thus accelerating the piston and shot particles 20 until the speed ofthe shot particles equals the speed of the shaft 15. This is the pointof maximum pressure of the trapped air in the compression chamber 18.

The equal and opposite forces applied by the trapped air to the piston19 and seal 17 now further accelerate the shot particles 20 and slow theshaft 15. If we assume the total mas of the shot particles 20 to beequal to the mass of the shot arrow 11 and neglect the effects offriction, the hereinabove described operation of the shot arrow 11 willcause the shot particles 20 to leave the shaft 15 and be propelledtoward the target while the shaft 15 and piston 19, having transferredall forward kinetic energy to the shot, lose all forward velocity andfall to the ground.

Although the piston 19 is initially forwardly propelled with the shotparticles 20, the pressure in the compression chamber 18 decreases belowambient as the piston moves forward of its initial position so that,before it can leave the shaft 15, the pressure in front of the piston issufficiently higher than the pressure in the compression chamber to pushthe piston back toward its original position. Only a small pressuredifferential is necessary because the piston is very light, and thetendency of the piston to leave the shaft is partially overcome byfriction. It should be noted, however, that some leakage of air, eitherinto or out of the compression chamber 18, may occur. Although thisleakage would not be sufficient to allow the piston 19 to leave theshaft 15, it may cause the final position of the piston to be noticeablydifferent from its position before the arrow 11 was fired. This may becorrected before a new load of shot particles 20 is loaded into theshaft 15 in a manner to be subsequently described herein with referenceto FIG. 5.

The separation of the shot 20 from the shaft 15 physically appears ascaused by an elastic collision between the shaft 15 and shot 20, thetrapped air serving as a transfer medium whereby substantially all theenergy applied to the shaft 15 by the bow 14 is transferred to the shot.If the shot arrow 11 is constructed so that the collision occurs at themoment the nock 16 leaves the bowstring 12, it can be seen thatsubstantially all of the energy of the bow will be transferred to thearrow and used to propel the shot particles 20 to their target. Thus, byusing the shot arrow of this invention, maximum transfer of the bowsenergy to the shot can be effected while the arrows shaft is made tofall near the archers feet for easy retrieval.

It should be noted that certain factors can cause slight deviations fromthe optimum operating conditions hereinabove described. For example,frictional interaction between the inner surface of the shaft 15 and thepiston 19 and shot particles 20 results in greater initial accelerationof the shot than would be produced by compression chamber pressurealone. This frictional interaction also prevents a complete transfer ofenergy so that some residual energy is retained by the shaft after theshot particles 20 have been expelled. However, it has been found thatthis only causes the shaft to travel a short distance (generally lessthan 10 ft.) before the shaft falls to the ground.

The adiabatic compression of the trapped air during the collision causesthe temperature of the air to increase greatly. Were a small quantity ofoil, or some other combustible material, inadvertently introduced in theshaft and subjected to this temperature, this high compressivetemperature could result in a small explosion which, while insufficientto damage the arrow, could tend to propel the shaft 15 rearwardly afterthe impact. Therefore, it is advantageous to construct the shot arrow 11so that the collision" and maximum air temperature occur shortly beforethe nock 16 leaves the bowstring 12.

This may be accomplished by elongating the rear seal so that it isconstructed substantially in the form illustrated as sea] 117 of'FIG. 3.It should be readily apparent that since the point of collision betweenthe piston and rear seal occurs when their velocities become equal, thepoint of collision is dependent upon the pressure buildup in thecompression chamber 18 and thus related to the length of the chamber.Accordingly, if the forward end portion of the seal 117 is extendedforwardly to decrease the length of the compression chamber 18, thepressure increase, and accordingly the acceleration of the piston 19,will occur at a greater rate so that the collision will occur at anearlier point in the flight of the shot arrow 11. By controlling thelength of the seal 117, the point of collision can be controlled so thatit occurs at any desired point. In this manner, the occurrence of thecollision before the nock leaves the bowstring 12 can be assuredso'that,

should diesel ignition of any combustibles in the shaft 15 occur, theresultant explosion will only serve to increase the energy imparted tothe shot particles and not likely present a hazard to the archer.

Further, it is well known that a recurve bow applies an additional forceto an arrow just before the arrow leaves the string. If the collisionand this last kick by the bow occur at about the same time, theeffective mass of the arrow being accelerated by the bow will beincreased to optimize the efficiency of the transfer of energy to thearrow during application of the recurve force, as will be readilyapparent to those skilled in the art.

Another embodiment of the seal is illustrated in FIG. 4 and designatedas seal 217. The point of collision of the arrow 11 can be controlledthrough the use of the seal 217 without any adjustment of the length ofthe seal. Only its position need be altered. When the seal 217 issecured in place by a suitable epoxy-type adhesive, the forward and rearobturating rims 2l7a'and 2171;, respectively, maintain the integrity ofthe air seals so that the seal 217 performs a function substantiallyidentical to the seal 117. It should be noted that due to the size ofthe seal 117 of FIG. 3, its use significantly increases the mass of theshot arrow 11 while no such increase is produced by use of the seal 217.Clearly, the embodiment of the seal described would depend upon the masswhich must be added to the shaft 15 to match the weight of the shotpropelling arrow 11 to that of the shot 20 for optimum performance ofthe shot arrow as previously described. For example, if *30 projectileswere to be fired, a more massive arrow would preferably be used and,accordingly, a heavier sealing means such as the seal 117 of FIG. 3 isdesirable. If 15 projectiles are fired, a lighter arrow and, possibly,the seal 217 would be required. Additionally, other sealing means may beused without departing from the spirit and scope of this invention.

As previously indicated, when the shot arrow 11 is fired, some air mayleakpast the piston 19, either into or out of the compression chamber18, so that the final position of the piston 19 is altered. To preservethe operating characteristics of the arrow, itis thus necessary to movethe piston 19 to its former rest position so that the compressionchamber 18 will be of proper length. For this purpose, an adjustingmeans such as an adjusting rod 21 shown in FIG. 5 may be used. Theadjusting rod 21 may be of any desired length sufficient to extendthrough the open forward end portion 15a of the shaft 15 and has athreaded end portion 21a for attachment to the threaded opening 190 ofthe piston 19.

It should be readily apparent that after attachment of the adjusting rod21 to the piston 19, the rod may be moved slowly to relocate the piston.This slow motion of the piston 19 will permit air to flow around it aswill be readily understood by those skilled in the art.

The final location of the piston 19 may be accurately determined by theuse of calibration marks 21b, one or more of which would be preferablypositioned on the adjusting rod 21. Alignment of a suitable calibrationmark 21b with the forward end portion 15a of the shaft 15 would showthat the piston 19 was properly positioned.

It it is desired to retain the shot particles 20 in the shaft 15 for anextended time period prior to shooting the shot arrow 11 or if there isa possibility that the shot may fall out of the shaft 15 before orduring firing, a suitable shot retaining means should be used.

FIG. 3 illustrates a retainer 22 which may be molded of rubber or othersuitable material and is shaped to have an inwardly directedcircumferential lip 22a. The retainer 22 is fitted onto the shaft 15with the circumferential lip 22a positioned against, and extendinginwardly of, the forward end portion 15a of the shaft. Thecircumferential lip 22a should be dimensioned to loosely hold the mostforwardly positioned shot particle 20 within the shaft 15 while the shotarrow 11 is at rest but to readily release the shot particles 20 with aminimum loss of energy of the particles when the arrow is fired. Theretainer 22 serves the additional function of protecting the forward endportion of the shaft 15 against damage when the shot arrow 11 falls tothe ground and helping to prevent dirt, grass or other debris fromentering the shaft 15. If desired, the lip 22a may be segmented or coveronly a portion of the periphery of the opening so that energy loss isminimized. The lip 22a need only hold the shot particles 20 againstbeing inadvertently allowed to fall from the open forward end portion15a of the shaft 15.

FIG. 4 illustrates an alternate shot retaining means in the form of aknock-off closure 24 which is preferably fitted over the forward endportion 15a of the shaft and is detached therefrom by the most forwardlydirected shot particle 20 when the arrow is fired.

In this manner, a shot propelling arrow is disclosed which effectivelypropels a plurality of shot particles toward a target transferringsubstantially all of the energy imparted by the bow thereto, the shotarrow falling to the ground within a few feet of the bow.

It should be understood that components of the shot arrow 11 may befurther modified if desired. For example, a rear seal may be usedwherein two generally frusto-conical members are threaded together toexpand a tubular plastic sleeve into tightly fitting, sealingrelationship within the shaft 15. Such a rear seal would function in amanner similar to the rear seal 217 of FIG. 4 and, additionally, couldbe moved within the shaft for removal or repositioning by loosening thethreaded members. Although the shot-arrow 11 has been described inconjunction with discrete, spherical steel shot particles 20, it shouldbe understood that other projectiles, including elongated projectiles,shot particles which are connected in one or more long chains, orprojectiles having a cylindrical or other desired shape may be usedwithout departing from the spirit and scope of this invention. The shotparticles 20 may be formed of any desired material having sifficienthardness to withstand the large magnitude forces produced when the shotpropelling arrow 11 is fired without significant deformation which woulddetract from the effectiveness of the arrow.

We claim:

1. An arrow for propelling a plurality of projectiles, said arrowcomprising a tubular shaft having an open forward end portion, a rearend portion and a generally uniform cross section, piston means mountedin slidable sealing relation in the shaft and defining a projectileholding portion in the shaft forwardly of the piston means, meanssealing the shaft rearwardly of the piston means, and compressible fluidin the shaft between the piston means and the sealing means, the pistonmeans including a forwardly directed threaded opening engageable by anadjusting rod having a threaded end portion for controlling the lengthof compressible fluid between the piston means and the sealing means.

2. An arrow as in claim 1 wherein nock means is attached at the rear endportion of said shaft for engaging a bowstring.

3. An arrow as in claim 1 wherein a calibration mark is provided at apredetermined location on said adjusting rod.

4. An arrow for propelling a plurality of projectiles, said arrowcomprising a tubular shaft having an open forward end portion, a rearend portion and a generally uniform cross section, piston means mountedin slidable sealing relation in the shaft, a plurality of linearlyaligned projectiles positioned in the shaft forwardly of the pistonmeans, a rear seal mounted in the shaft rearwardly of the piston means,and compressible fluid in the shaft between the piston means and thesealing means, the weight of the plurality of projectiles beingsubstantially equal to the total weight of the tubular shaft, pistonmeans and rear seal.

5. An arrow as in claim 4 wherein said rear seal has a forward endportion, said piston means and the forward end portion of said sealingmeans define a compression chamber in said shaft, and the forward endportion of said rear seal is positioned to provide a predeterminedlength for the compression chamber.

6. An arrow as in claim 4 including projectile retaining means mountedat the forward end portion of said shaft.

7. An arrow as in claim 6 wherein said projectile retaining meanscomprises a knock-off closure.

8. An arrow as in claim 6 wherein said projectile retaining meanscomprises inwardly directed lip means blocking a portion of the openforward end portion of said shaft.

9. An arrow as in claim 8 wherein said lip means is a continuousperipheral lip.

10. An arrow as in claim 4 wherein said compressible fluid is air.

11. A projectile propelling bow and arrow system comprising a bowincluding a bowstring and an arrow, separable from the bow upon releaseof the bowstring, the arrow comprising a tubular shaft having an openforward end portion and a nocked rear end portion for engaging thebowstring, piston means mounted in slidable sealing relation in theshaft, sealing means mounted in the shaft, compressible fluid in theshaft between the piston means and the sealing means, and a plurality ofprojectiles positioned in the shaft forwardly of the piston means, thedistance between the piston means and the sealing means permittingmaximum compression of the compressible fluid just prior to separationof the arrow from the bowstring upon release of the bowstring.

12. A projectile propelling bow and arrow system as in claim 11 whereinsaid projectiles are metallic and generally spherical in shape.

13. A projectile propelling bow and arrow system as in claim 11 whereinsaid compressible fluid is air.

14. A projectile propelling bow and arrow system as in claim 11 whereinsaid projectiles are disposed in a line axially aligned in said shaft.

15. A projectile propelling bow and arrow system as in claim 11 whereinthe weight of said plurality of projectiles is substantially equal .tothe total weight of said tubular shaft, said piston means and saidsealing means.

1. An arrow for propelling a plurality of projectiles, said arrowcomprising a tubular shaft having an open forward end portion, a rearend portion and a generally uniform cross section, piston means mountedin slidable sealing relation in the shaft and defining a projectileholding portion in the shaft forwardly of the piston means, meanssealing the shaft rearwardly of the piston means, and compressible fluidin the shaft between the piston means and the sealing means, the pistonmeans including a forwardly directed threaded opening engageable by anadjusting rod having a threaded end portion for controlling the lengthof compressible fluid between the piston means and the sealing means. 2.An arrow as in claim 1 wherein nock means is attached at the rear endportion of said shaft for engaging a bowstring.
 3. An arrow as in claim1 wherein a calibration mark is provided at a predetermined location onsaid adjusting rod.
 4. An arrow for propelling a plurality ofprojectiles, said arrow comprising a tubular shaft having an openforward end portion, a rear end portion and a generally uniform crosssection, piston means mounted in slidable sealing relation in the shaft,a plurality of linearly aligned projectiles positioned in the shaftforwardly of the piston means, a rear seal mounted in the shaftrearwardly of the piston means, and compressible fluid in the shaftbetween the piston means and the sealing means, the weight of theplurality of projectiles being substantially equal to the total weightof the tubular shaft, piston means and rear seal.
 5. An arrow as inclaim 4 wherein said rear seal has a forward end portion, said pistonmeans and the forward end portion of said sealing means define acompression chamber in said shaft, and the forward end portion of saidrear seal is positioned to provide a predetermined length for thecompression chamber.
 6. An arrow as in claim 4 including projectileretaining means mounted at the forward end portion of said shaft.
 7. Anarrow as in claim 6 wherein said projectile retaining means comprises aknoCk-off closure.
 8. An arrow as in claim 6 wherein said projectileretaining means comprises inwardly directed lip means blocking a portionof the open forward end portion of said shaft.
 9. An arrow as in claim 8wherein said lip means is a continuous peripheral lip.
 10. An arrow asin claim 4 wherein said compressible fluid is air.
 11. A projectilepropelling bow and arrow system comprising a bow including a bowstringand an arrow, separable from the bow upon release of the bowstring, thearrow comprising a tubular shaft having an open forward end portion anda nocked rear end portion for engaging the bowstring, piston meansmounted in slidable sealing relation in the shaft, sealing means mountedin the shaft, compressible fluid in the shaft between the piston meansand the sealing means, and a plurality of projectiles positioned in theshaft forwardly of the piston means, the distance between the pistonmeans and the sealing means permitting maximum compression of thecompressible fluid just prior to separation of the arrow from thebowstring upon release of the bowstring.
 12. A projectile propelling bowand arrow system as in claim 11 wherein said projectiles are metallicand generally spherical in shape.
 13. A projectile propelling bow andarrow system as in claim 11 wherein said compressible fluid is air. 14.A projectile propelling bow and arrow system as in claim 11 wherein saidprojectiles are disposed in a line axially aligned in said shaft.
 15. Aprojectile propelling bow and arrow system as in claim 11 wherein theweight of said plurality of projectiles is substantially equal to thetotal weight of said tubular shaft, said piston means and said sealingmeans.